What is Thoracocentesis?

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Last updated: February 8, 2025View editorial policy

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From the Guidelines

Thoracocentesis is a medical procedure that involves removing fluid from the pleural space for diagnostic or therapeutic purposes.

Key Points

  • Thoracentesis is recommended for patients with suspected lung cancer who present with a pleural effusion to differentiate between a malignant effusion and a paramalignant effusion 1.
  • The procedure can be performed under ultrasound guidance, which improves the success rate and reduces the incidence of iatrogenic pneumothorax 1.
  • Pleural fluid cytology is a quick and minimally invasive way to diagnose malignant effusions, with a mean sensitivity rate of about 72% when at least two pleural fluid specimens are submitted 1.
  • The diagnostic yield of pleural fluid cytology depends on sample preparation, the experience of the cytologist, and the tumor type, with the highest diagnostic yields retrieved in patients with adenocarcinoma 1.
  • Ultrasound-guided thoracentesis is recommended for performing diagnostic thoracentesis due to its improved success rate and reduced risk of pneumothorax 1.

Procedure Details

  • The procedure involves removing fluid from the pleural space using a needle or catheter.
  • The fluid is then sent for cytologic examination to diagnose malignant effusions.
  • Ultrasound guidance can help identify the optimal site for needle insertion and reduce the risk of complications.
  • The volume of fluid needed for cytologic evaluation varies, but submitting more than 50 mL of pleural fluid does not increase the diagnostic yield 1.

From the Research

Definition and Purpose of Thoracocentesis

  • Thoracocentesis is a medical procedure that involves removing fluid from the pleural space for diagnostic or therapeutic purposes 2, 3, 4, 5, 6.
  • The procedure is commonly used to evaluate pleural effusions, which are accumulations of fluid in the pleural space that can be caused by a variety of conditions, including infections, cancers, and heart failure.

Clinical Value and Complications

  • Thoracocentesis is a clinically valuable procedure that can provide useful information for diagnosis and treatment 3.
  • However, the procedure is not without risks, and complications can occur, including pneumothorax, bleeding, and re-expansion pulmonary edema 2, 3, 4.
  • The risk of complications can be reduced by using optimal procedural techniques, such as ultrasound imaging, and by having experienced clinicians perform the procedure 2, 4.

Safety and Risk Factors

  • The safety of thoracocentesis has been evaluated in several studies, and the results suggest that the procedure can be safely performed in patients with uncorrected bleeding risk 6.
  • However, the presence of certain risk factors, such as coagulopathy or thrombocytopenia, may increase the risk of complications 2, 6.
  • The use of ultrasound imaging and other procedural modifications can help to reduce the risk of complications and improve the safety of thoracocentesis 4, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Improving the safety of thoracentesis.

Current opinion in pulmonary medicine, 2011

Research

Advances and Controversies in Thoracentesis and Medical Thoracoscopy.

Seminars in respiratory and critical care medicine, 2019

Research

The safety of thoracentesis in patients with uncorrected bleeding risk.

Annals of the American Thoracic Society, 2013

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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